The interior of the NIF target chamber. The service module carrying technicians can be seen on the left. The target positioner, which holds the target, is on the right. [Photo: NIF] On March 15, scientists at the Lawrence Livermore National Laboratory fired 192 laser beams inside the National Ignition Facility (NIF). The infrared lasers were concentrated into a single beam of ultraviolet energy that topped out at 2.03 megajoules, making it the most powerful laser in history--and the world’s first 2-megajoule ultraviolet laser.

The chamber was designed to accomodate a 1.8-megajoule laser; such a laser would easily trounce the previous world-record 1.6-megajoule laser. The focused beam, however, managed to reach an initial 1.875 megajoules, and surpassed the 2-million-joule marker after passing through the final focusing lenses.

Although the laser shot exceeded the scientists’ expectations, it did relatively little damage to the NIF’s laser optics. The scientists fired a second shot 36 hours after the world-record moment, and the laser will eventually be able to fire 15 times per second.

A NIF target contains a polished capsule about two millimeters in diameter, filled with cryogenic (super-cooled) hydrogen fuel. [Photo: NIF]

The whole point of this super-powerful laser is to produce a nuclear fusion reaction by fusing hydrogen isotopes. Yes, you read that right: nuclear fusion, the same energy-producing reaction that occurs in our Sun.

Later this year, scientists will fire the lasers at a target of hydrogen fuel--the experiment that the NIF chamber was designed to accommodate.